Peel and chop the kiwi fruit, hull and halve the strawberries and roughly chop the watermelon.

Puree each fruit separately in a blender or liquidizer with 1 tablespoon sugar, until really smooth. Set aside.

Put each fruit puree separately into a cocktail shaker and add 5 tablespoons iced vodka and a little crushed ice. Replace the lid and shake vigorously for about 30 seconds, remove the lid and pour into 4 martini glasses. Decorate each glass with a slice of fruit and serve immediately.